1. Field of Invention
The invention relates to an intermediate transfer type color image forming apparatus.
2. Description of Related Art
There has been a color image forming apparatus that includes developing cartridges for yellow, magenta, cyan and black toners, a photosensitive medium, an intermediate transfer medium, and an transfer roller, in its casing.
First, a color-by-color visible image is sequentially formed on the photosensitive medium then transferred to the intermediate transfer medium by sequentially using yellow, magenta, cyan and black toners supplied by the respective developing cartridges. Thus, a color image is formed on the intermediate transfer medium. The color image is transferred onto a sheet by the transfer roller, and finally, a color image is formed on the sheet.
The developing cartridges can be attached to and detached from the image forming apparatus by opening a front cover of the casing. The photosensitive medium can also be attached to and detached from the image forming apparatus by opening an upper cover of the casing.
However, as described above, this structure requires opening different covers to attach/detach the parts to/from the image forming apparatus, resulting in making the replacement of the parts and maintenance of the image forming apparatus cumbersome and complicated.
The invention achieves simplification and speedup of the procedures for the replacement and maintenance of parts.
An image forming apparatus, in accordance with the invention, includes a developing device, a photosensitive medium and an intermediate transfer medium, in its casing. A processing unit includes the developing device and the photosensitive medium, and an intermediate transfer unit includes the intermediate transfer medium. The processing unit is attached to and detached from the intermediate transfer unit in a common direction when only the processing unit is removed from the casing and the intermediate transfer unit is attached to and detached from the casing in the common direction when the processing unit integrated with the intermediate transfer unit is removed from the casing.
Because the processing unit is detached from the casing separated from the intermediate transfer unit, maintenance can be performed on the developing device and the photosensitive medium. When the processing unit is detached from the casing integrated with the intermediate transfer unit, maintenance can be further performed on the intermediate transfer medium.
That is, the maintenance can be performed on all or any of the developing device, the photosensitive medium and the intermediate transfer medium in a single detaching/attaching operation. Thus, replacement and maintenance of the developing device, the photosensitive medium and the intermediate transfer medium can be easily and speedily performed.
The processing unit and the intermediate transfer unit can be detached and attached in the same direction, so that operability becomes high.
A feed unit can be detached and attached in the same direction as the attaching/detaching direction of the processing unit and the intermediate transfer unit. Accordingly the operability of the whole image forming apparatus can be improved.
The processing unit can be a combination of a developing device unit, on which the developing device is detachably attached, and a photosensitive medium unit, on which the photosensitive medium is attached with both units detachably attached to each other. In this structure, the developing device unit can designed so as to be detached and attached with respect to the casing integrated with or separated from the photosensitive medium unit.